Alternatives to Unison

Synchronize two file collections while preserving changes from both sides. The listings below can replace it for an important use case. Each note says what changes if you switch.

Replacements

Listings that take over the same core job as Unison.

  • Syncthing

    Keeps folders identical across your own machines, directly between them, with no cloud account in the middle.

    FreeOpen sourceWindowsmacOSLinuxCommand lineSelf-hosted

    Syncthing runs continuous real-time sync across several machines with versioning and conflict handling, under MPL-2.0, rather than reconciling two replicas on demand.

  • FreeFileSync

    Compares two folders, shows exactly what differs, and copies only what changed.

    FreeOpen sourceWindowsmacOSLinux

    FreeFileSync offers a graphical two-way mode with versioning and saved batch jobs, but some conveniences are reserved for the paid Donation Edition.

  • GoodSync

    Block-level file sync and backup with versioning and many back ends.

    PaidProprietaryWindowsmacOSLinuxAndroidiOS

    GoodSync provides two-way block-level sync with versioning and mobile apps, but it requires a paid per-user licence and is closed source.

  • Resilio Sync

    Peer-to-peer file sync with no cloud server in the middle.

    FreeProprietaryWindowsmacOSLinuxAndroidiOS

    Resilio Sync syncs folders peer to peer with mobile apps and handles very large libraries well, but it is closed source rather than GPL-3.0.

  • rsync

    The classic delta-transfer tool for copying and mirroring files.

    FreeOpen sourceWindowsmacOSLinuxCommand line

    rsync, also GPL-3.0, transfers only changed parts of files and preserves permissions, but it copies in one direction and does not merge changes from both sides.

  • osync

    Two-way file synchronization script built on rsync with fault tolerance and near real-time sync.

    FreeOpen sourceLinuxCommand line

    osync performs two-way sync on top of rsync with fault tolerance and a near real-time mode, but it is command-line only on Unix-like systems.

  • Syncovery

    A file sync, backup and migration tool for local drives, network shares and cloud storage.

    PaidProprietaryWindowsmacOSLinux

    Syncovery handles sync and backup across local, network and cloud storage on Windows, Mac and Linux, but it is paid, closed source and takes time to learn.

Also worth comparing

These listings name Unison as their own alternative, so the relationship runs both ways.

  • Beyond Compare

    A tool for comparing, merging and synchronizing files and folders on Windows, macOS and Linux.

    PaidProprietaryWindowsmacOSLinux

    Unison is free under GPL-3.0 and preserves changes from both sides of a sync, but offers no text, image or table comparison views.

  • ChronoSync

    A Mac app for synchronizing and backing up folders to drives, other Macs, NAS and cloud services.

    PaidProprietarymacOS

    Unison is free and open source under GPL-3.0 and preserves changes on both sides, but lacks ChronoSync's bootable backups and cloud destinations.

  • git-annex

    A command-line tool that manages and syncs large files with git without storing their contents in git.

    FreeOpen sourceLinuxCommand line

    Unison is GPL-3.0 open source and syncs two file collections both ways with a far gentler learning curve, but does not track content across many drives.

  • Lsyncd

    A live syncing daemon that watches local directories and mirrors changes to remote targets with rsync.

    FreeOpen sourceLinuxCommand line

    Unison synchronizes two file collections in both directions on Windows, macOS and Linux, though conflicting edits may need a decision.

  • Mutagen

    Open-source tool for real-time file sync and network forwarding between local machines and remote containers.

    FreeOpen sourceCommand line

    Unison synchronizes two file collections in both directions on Windows, macOS and Linux, but lacks Mutagen's network forwarding and container support.

  • Rclone

    A command line tool that syncs, copies and mounts files across more than seventy cloud storage services.

    FreeOpen sourceWindowsmacOSLinuxCommand line

    Unison synchronizes two file collections while keeping changes made on both sides, but it lacks rclone's cloud provider support, mounting and client-side encryption.

Similar software

Related functionality, not a direct replacement.